RENO, Nev.—A federal judge is allowing the Bureau of Land Management to resume the roundup of dozens of wild mustangs in northern Nevada but only under specific conditions she says are necessary to alleviate concerns that the animals are treated inhumanely, including limiting use of electric cattle prods.

U.S. District Judge Miranda Du said in a formal order Thursday lifting an injunction blocking the roundup that BLM wranglers can shock horses with cattle prods only when necessary to ensure the safety and security of horses and handlers.

The judge also said BLM contract helicopter pilots must make sure slower, young foals aren’t separated from their herd during the chase. And she specifically forbid the agency from driving horses into barbed-wire fences, as they did earlier in the roundup near the Idaho line.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP’s earlier story is below.

A federal judge has agreed to let the U.S. Bureau of Land Management resume the roundup of dozens of wild mustangs in northern Nevada but says she remains concerned about critics’ complaints the agency is treating the animals inhumanely.

U.S District Judge Miranda Du explained Thursday she was granting the government’s request to lift an emergency injunction says she remains concerned about critics’ complaints the agency is treating the animals inhumanely.

U.S District Judge Miranda Du explained Thursday she was granting the government’s request to lift an emergency injunction that halted the roundup last week because opponents had failed to prove the agency lacked authority to remove the mustangs from the high desert near the Idaho line.

The judge said she intended to issue a formal order on Friday but hadn’t decided yet if it’s necessary to include specific restrictions to ensure the roundup is conducted humanely after BLM wranglers were recently captured on video repeatedly shocking mustangs with electric prods and in one case chasing several into a barbed wire fence with a helicopter.

“I will craft the order to ensure the matter is conducted in a humane manner,” Du said at the conclusion of a two-hour hearing, adding she hadn’t determined yet if BLM’s actions constituted inhumane treatment under the law.

She told BLM’s lawyer from the Justice Department that the agency could resume the roundup first thing Friday even if her order hasn’t been formalized by then but cautioned, “you’re taking the risk the methods you use could be prohibited in the order.”

Du earlier told BLM she was willing to postpone Thursday’s hearing so agency experts could have more time to provide evidence and testimony to help prove the treatment is not inhumane.

But Justice Department lawyer Erik Petersen said the delay in the roundup already has added $100,000 to the cost of the gather of the additional 50 horses because the contractors are sitting idle but still being paid.

“The plaintiffs have got us in a bind. It’s costing taxpayers $20,000 a day,” he said. “My client’s goal is to get this injunction lifted today and resume the gather tomorrow.”

BLM argues the herd in the Owyhee Horse Management Area is too large to be sustained given lingering drought and warned that some of the animals may die if they are not removed before spring.

“To whatever extent that plaintiff might be harmed by the gather, that harm is not irreparable in light of the fact that the gather is designed to promote the health of the wild horses in the Owyhee Complex, thereby ensuring the continued existence of thriving, free-ranging herds on the range,” BLM’s lawyers wrote in court briefs filed before the hearing.

Wild horse protection advocates countered by accusing the agency of shamefully exaggerating the threat to the animals in an area

“I think it is fiction, your honor,” said Gordon Cowan, a Reno lawyer for the plaintiff, Laura Leigh and her Wild Horse Education group. “There’s really no emergency out there. There’s no proof of stress on the range.”

Cowan also argued that it is “BLM’s choice to waste $20,000 per day in budget funds is its own choosing rather than those of the court or Ms. Leigh’s.” He accused the BLM of engaging in “shameful scare tactics” intended to “dissuade, censor, intimidate or silence those like Ms. Leigh who, in good faith, bring an agency’s bad conduct to light.”

Cowan said it’s part of a pattern of intimidation and pointed to a confrontation between Interior Secretary Ken Salazar and a reporter for a Colorado Springs, Colo., newspaper who was questioning him about wild horses in November.

“This is the same agency whose top leader, the secretary of Interior, threatened to punch out a journalist when inquiring of the BLM’s links to selling wild horses to a ‘kill buyer’ for slaughter,” Cowan wrote in a footnote to court briefs filed on Wednesday.